Remove unused and odd code.

Remove unused and odd code.

This code was never being used and any use of it would look fairly strange.
For example, it would try to map a object_error::parse_failed to
std::errc::invalid_argument.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210912 91177308-0d34-0410-b5e6-96231b3b80d8